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How GSM Affects The Quality Of Your Mattress | Winstons

When it comes to choosing the perfect mattress, there are an abundance of factors that can influence your decision. To achieve the perfect balance between quality and value, GSM is arguably the most important element to consider – Let’s find out why.

What’s Inside Your Mattress?

Grams per Square Meter (GSM) is something mattress manufacturers and retailers do not want you to know when buying a new mattress. But, once you know and understand why GSM is important, you’ve got the upper hand in finding out precisely what’s inside your mattress and whether or not the mattress is worth the money you are paying. We reveal why the retailers and manufacturers hide this detail and how you can find out what’s inside your mattress—helping you not waste money.

Unfortunately, most mattress manufacturers and retailers withhold essential information regarding the design and construction of mattresses. Hopefully, this guide will remind you always to ask, ‘What’s the GSM of the natural fillings in this mattress?’.

You may have never seen the reference GSM before when shopping for a mattress, which proves how tight-lipped the mattress industry is. So let’s dig a little deeper to show why you need to know the GSM.

natural mattress fibres

What is GSM?

GSM simply stands for grams per square metre and describes the weight of the filling within the mattress itself. In other words, GSM is the density of fibres within the mattress. 

The measurement of GSM is rooted in the craft of upholstery and provides an accurate summary of the density of a mattress. The key thing to note is that the higher the GSM, the higher the quality of the mattress.

It also provides a standardised benchmark that allows manufacturers to easily compare the density of mattresses, even if they’re made from different materials. Whether a mattress is made from white fibre, wool, horsehair or even a combination of fibres, GSM provides a simple like-for-like comparison. 

However, many mattress retailers fail to pass on GSM measurements to their consumers. Unfortunately, they know that they can sell lower quality mattresses at a higher price to increase their profits. 

Without understanding GSM, you can easily fall into the trap of paying more for a mattress that is actually worth less. Therefore, it’s crucial that you find out the GSM of a mattress to ensure that you’re getting the best possible value.

Is the Quality of the Mattress Dependant on the GSM?

Mattress retailers hide the GSM because they don’t want you to make comparisons between mattress brands and models. Without this information, you will struggle to compare and choose a new mattress correctly. This way, saleswomen and men can promote finance, discounts and other sales methods to you until you decide on whichever mattress you think is the best, emphasising the word ‘think. Of course, it would be better to know which mattress gave you the most value for your money in an ideal world.

Take cotton as an example

  • Cotton comes in weights of 650GSM / 1250GSM
  • Two mattresses are displayed as having cotton fibre
  • One has 650GSM cotton, whereas the other mattress has 1250GSM
  • They are both retailing at £1000

Unless you know which mattress has the 1250GSM cotton, you will never know which mattress is the higher quality mattress but you will pay the same price.

Why is GSM Important?

GSM is extremely important when it comes to choosing a mattress for a number of reasons:

First and foremost, a mattress with a high GSM will provide a much more supportive, plusher and more comfortable feel as the density of the upholstery is much thicker and fuller.

Additionally, a mattress with a high GSM is likely to last much longer as it will not be displaced by your body weight as easily as a mattress with a low GSM. Leading to a much better night’s sleep, for many years to come.

Not only that, understanding GSM will help you to get the maximum value out of your mattress. All too often, mattress price points are not based on GSM and therefore, you could be purchasing a low-quality mattress with a really low GSM for the same price as a much higher quality mattress with a high GSM. It’s crucial to find out the GSM of a mattress before purchasing in order to avoid this and truly make the most of your investment.

GSM is a brilliant tool for making direct comparisons between mattresses that may be made from different materials or have different dimensions. GSM provides a like-for-like comparison and allows you to easily assess the difference in quality between two mattresses – Making your decision much easier.

We’ve created a handy table to help you easily identify the quality of our mattresses:

GSM Type Price 
A minimum of 1600GSM Double Sided £300-£800
A minimum of 3500GSM Double Sided £800-£1000
A minimum of 4300GSM Double Sided £1000-£1800
A minimum of 4600GSM Double Sided £1800-£2100
A minimum of 6000GSM Double Sided £2100+


Is it Essential to Know the GSM?

Yes, it is! The mattress fillings are the most costly part of your mattress, and so you must know that what’s inside the mattress is worth the money. This is why GSM is rarely ever stated by retailers, online stores and manufacturers, as it’s the one thing they do not want you to ask or know about, so be cautious of mattress stores that say to you, they don’t know.

What GSM Should you Look for in a Luxury Mattress?

When buying a new mattress, make sure that you choose the one with the greatest amount of high-quality natural fillings. Higher GSM of fillings will ensure settlement, indents and body impressions do not alter the mattress over time and provide significantly more comfort and support.

The points below will illustrate the minimum you should expect for the overall total GSM for mattress price points.

GSM Natural Fibre Content Price 
A minimum of 3500GSM 100% Natural £800-£1000
A minimum of 4300GSM 100% Natural £1000-£1800
A minimum of 4600GSM 100% Natural £1800-£2100
A minimum of 6000GSM 100% Natural £2100+

If a retailer’s prices are higher with less GSM or natural fibre content, you should ask them why? And don’t let them give the speel of GSM is not important or their costs are higher because of the springs they use or the handcrafting is expensive as all high-end luxury mattress brands have a similar costs for springs, labour and mattress ticking. It’s the fillings that will make the mattress more expensive so for example:

Mattress 1 

  • GSM: 5400
  • Natural Fibre: 100%
  • Fibres: Alpaca Wool, British Wool, Horsetail, Flax
  • Rows Hand-Side Stitching: 4
  • Mattress Ticking: 100% Chemical Free Cotton
  • Springs: 2008 Calico Springs
  • Price: £4260

Mattress 2

  • GSM: 6600
  • Natural Fibre: 100%
  • Fibres: British Pure Wool, British Fleece Wool & Cotton, Hand Teased Shropshire Wool, Hand Teased Loose Long Curled Horsetail, British Highland Wool & Natural Hessian
  • Rows Hand-Side Stitching: 4
  • Mattress Ticking: 100% Chemical Free Cotton
  • Springs: 1600 Calico Springs
  • Price: £2099.99

So why Does Mattress 1 Cost More?

Because the retailer selling Mattress 1 has a much higher markup. By seeing the above examples, it is clear that mattress 2 is superior to mattress 1 as it has more GSM of fillings, the same amount of rows of hand side stitching, the same outer cover and it only has 400 less springs which will make no difference regarding support and does not warrant a further £2160 in cost. But, without knowing the GSM, you would not be able to make an educated decision on which mattress is better. The bottom line will always be the more GSM of natural fibres the better quality the mattress and value for money.

Once you understand GSM and why it’s so important, you will know what to look for when reading through mattress descriptions. We hope that all mattress retailers will eventually list their products the same way food corporations do, with a detailed summary showing components and weight.

There really should be no reason for the necessary detail on what’s inside your mattress before you hand over thousands of pounds isn’t already given to you so you can make a fair comparison.

Now you are equipped with the knowledge you need to make an informed decision, we wish you all the luck in finding the right mattress for you. 

At Winstons Beds, we are always transparent in terms of the GSM of our mattress fillings. Therefore, you can rest assured that you will always get the highest quality mattress, for the best possible value. If you’re not sure which GSM mattress filling will suit you, don’t hesitate to get in touch and we’ll be happy to provide our expert opinion.

Published: 11th November 2020 (Updated: 2nd September 2023) | Graham

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